Interconnection patterns between a digital baseband module and a radio module are specific to each industrialist and/or are dedicated to a given application. The baseband subsystem (BB) must have precise knowledge of the design and the real-time behavior of the radio frequency equipment (RF) with which it is associated. The baseband and radio frequency subsystems have a high level of interdependence. In fact, they are not or not very reusable. Moreover, the architectures are not modular.
The known architectures of the applicant are based on the use of analog signals on intermediate frequency IF or otherwise and/or specific digital signals and/or a set of discrete signals, bearing all or some of the real-time and functional constraints related to the design of the radio subsystem (trigger, specific timings, characteristic frequencies, clock, command signals, etc.). The known systems and architectures of the applicant are not modular and do not allow themselves to be easily evolved. Due to the high level of coupling between the BB and RF subsystems of the prior art, the existing structures do not provide opportunities for interchangeability or evolutions of one or the other of the subsystems without resorting to a resumption of developments.
The functional and behavioral characteristics, the capabilities, the performances and notably the real-time sequencing to be fulfill that are associated with the RF subsystem need to be taken into account in a precise manner in the baseband BB subsystem. Even in the most accomplished prior architectures, the exchange mechanisms between the BB and RF are synchronous, which imposes constraints on the hardware and software design of the BB; control over real time must be implemented finely in the BB.
The patent EP 2 107 684 describes an interface architecture according to which the processing times for the various commands of the radio module must be known from baseband and integrated into the operations of the baseband application that is executed on it.